JP2002301557A - Purge cover device of metal injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a purge cover device capable of easily, rapidly and safely purging the molten metal in a metal injection molding machine without damaging any equipment. SOLUTION: A purge plate 16 shaped for shielding the forward part of a nozzle 3 is installed inside a purge cover 11 which is installed at a position in contact with a fixed plate 12 to cover the opened top side, front side and back side around the nozzle 3 in a U-shape. During the injection molding, the purge plate 16 is allowed to slide to an evacuation position not interfering with the nozzle 3, a heating cylinder 1, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a purge cover device for an injection nozzle in a metal injection molding machine for injection molding a low melting point metal material such as a magnesium alloy, an aluminum alloy, and a zinc alloy.

[0002]

2. Description of the Related Art FIG. 5 shows a purge cover device of a conventional metal injection molding machine.

In metal injection molding, solidified grains, cut pieces, crushed grains, etc. of a low melting metal material (hereinafter referred to as material chips).
Is put into a material hopper (not shown) attached to the rear part of the heating cylinder 1, heated and kneaded in the heating cylinder 1 to become a molten or semi-molten material (hereinafter, referred to as a molten metal), and is sent forward. It is stored in a front chamber (not shown) in the heating cylinder 1.

After the molten metal stored in the front chamber of the heating cylinder 1 reaches a predetermined amount, the entire injection device 2 to which the heating cylinder 1 is attached is advanced, and the nozzle 3 attached to the tip of the heating cylinder 1 is moved. Abuts against the sprue bush 6 of the mold 5 which is fixed to the mold clamping device 4 and closed in advance. Next, an injection cylinder (not shown) incorporated in the injection device 2 is driven to the forward side, and a screw or plunger (not shown) inserted into the heating cylinder 1 advances (hereinafter, this operation is referred to as injection).
Then, the molten metal stored in the front chamber in the heating cylinder 1 passes through the nozzle 3 and the sprue hole 7 in the mold 5, and is filled in the cavity 8 in the mold 5.

After the molten metal filled in the cavity 8 in the mold 5 is cooled and solidified, the mold clamping device 4 is driven to open the mold 5 and the cooled and solidified molten metal is taken out as a molded product.

[0006] By repeating the above-described steps, a metal molded product is continuously formed.

However, at the beginning of the molding operation, the molten metal injected from the chisel 3 into the mold 5 is not uniform, or the molten metal becomes uneven during the molding operation. The injection device 2 is retracted, and the nozzle 3 is
It is necessary to discharge the molten metal in the heating cylinder 1 from the nozzle 3 in a state where the molten metal is separated from the nozzle 3 (hereinafter, referred to as purge).

[0008] The molten metal discharged from the nozzle 3 by the purge is extremely high temperature (for example, about 600 ° C in the case of a magnesium alloy) for a human body, and, like a magnesium alloy, violently oxidizes in the atmosphere, ie, flame and white smoke. Since some materials may cause combustion accompanied by the following, drop them into a purge tray 10 containing dried casting sand 9 and the like, cover the molten metal with casting sand 9 and the like, and extinguish it with cooling and extinguishing in a state where oxygen is cut off. Have been.

In the above-mentioned purging operation, if the speed of the molten metal discharged from the nozzle 3 is too high, the molten metal may not fall well into the purge tray 10 and may scatter around. During the molding operation, the nozzle 3 and the sprue
In some cases, the contact state becomes uneven, and the molten metal leaks or spouts out from between the two.

[0010] As a safety device for eliminating the danger of high temperature and molten metal scattering around the nozzle 3,
The purge cover device is installed. The purge cover 11 of the purge cover device has a U-shape that covers the upper surface, the front surface, and the rear surface. The purge cover 11 is installed at a position in contact with the fixed plate 12, and is fixed to the fixed plate 12 or the molding machine base with bolts or the like. ing. In addition, the inspection door 1 having a transparent glass window 47 on the front side, that is, the side on which the driver stands (hereinafter, referred to as an operation side).
3 is provided, and a limit switch 14 is attached as an interlock of the inspection door 13.

As described above, the conventional purge cover 11
Covers the open top, front, and back surfaces around the nozzle 3 in a U-shape.
It does not touch high-temperature parts such as the surface, and the molten metal scattered from the nozzle 3 is also prevented from directly hitting an operator or the like.
Also, the purge cover 11 itself is fixed with bolts or the like.
2 and so on, there is no danger that the molding machine can be easily removed and operated.

Further, since the inspection door 13 is provided on the operation side, the periphery of the nozzle 3 can be inspected and cleaned without removing the purge cover 11. Further, when the inspection door 13 is opened, the limit switch 14 is operated, and the interlock of the control device of the molding machine is activated so that the injection operation and the purge operation cannot be performed. Work can be done safely.

[0013]

In the ordinary purging operation, the discharge speed of the molten metal is set to a low speed so that the molten metal flows directly from the nozzle 3 to the purge tray 10. However, if the purge speed is incorrectly set to a high value, the molten metal directly reaches the inner surface of the nozzle insertion hole 15 of the fixed platen 12 or the spool bush 6 of the mold 5 and adheres or adheres, making the removal operation difficult. And hinders the continuation of the molding operation.

Therefore, the nozzle insertion hole 15 of the fixed plate 12
Although a plate (hereinafter, referred to as a purge plate) for receiving the purged molten metal is inserted inside or outside thereof to prevent the molten metal from sticking to the spool bush 6 or the like, it becomes an obstacle during molding. Must be removed. For this reason, every time the purging operation is performed, the operation of inserting and removing the purge plate from the high-temperature location
It was a complicated and dangerous operation.

Further, due to the increase in the injection speed accompanying the improvement in the performance of the molding machine, the molten metal scattered from the nozzle 3 hits the fixed platen 12 and the mold 5 and rebounds, and scatters toward the rear side of the purge cover 11, ie, toward the injection device. It is also necessary to deal with so-called secondary scattering.

A purge plate placed in front of the nozzle 3 at the time of the purging operation is used to connect the nozzle 3 to the spool bush 6 at the time of molding.
Must be removed from a position in front of the nozzle 3 to make contact with the nozzle 3. If the nozzle 3 is advanced while the purge plate remains, and the two collide with each other, the heater 17 attached to the surface of the purge plate and the nozzle 3 and its electric wiring are damaged.

The molten metal scattered secondarily passes through the gap between the rear side of the purge cover 11, that is, the injection device side and a heat insulating material (not shown) wound around the outer surface of the heating cylinder 1 or the outside of the heating cylinder 1. Scattered, and may damage equipment existing in that direction, or cause harm to workers.

The upper part of the purge cover 11, that is, the upper surface,
When the front, back and side surfaces are closed, the purge cover 11
The internal air is heated to a high temperature, and the reliability of parts having low heat resistance such as electric wiring is reduced. Also, when the inspection door 13 is opened and the work is performed, the worker is exposed to the high-temperature air accumulated inside the purge cover 11. There is a risk of being done. In particular, if the upper part is shielded, the inside of the purge cover 11 becomes dark, and the workability is reduced, and a dedicated lighting means is required.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to easily, quickly, and safely perform a purge operation of a molten metal in a metal injection molding machine and without damaging equipment. It is an object of the present invention to provide a purge cover device capable of performing the following.

[0020]

In the purge cover device according to the present invention, a purge plate that blocks the front of the nozzle is installed inside a purge cover that is installed so as to be in contact with the fixed platen. It can be slid to a retracted position such as a nozzle or a heating cylinder that does not interfere.

In addition, a confirmation means for confirming that the purge plate has been slid to the retracted position is provided, and a holding means for retaining the purge plate at the retracted position is provided.

Further, a rear plate is provided at the rear of the purge cover so as not to interfere with the outer surface of the heating cylinder or a heat insulating material attached to the outside of the heating cylinder. Further, a slide means for sliding the purge plate from outside the purge cover is provided.

When performing a purging operation using the above apparatus, the purge plate is slid forward of the nozzle. As a result, the molten metal purged from the nozzle is received by the purge plate, and falls into the purge tray below.

When performing a molding operation, the purge plate is slid to the retracted position. Thus, the nozzle comes into contact with the spool bush without colliding with the purge plate, and the injection operation into the mold becomes possible.

When the molten metal scattered secondarily passes through the gap between the purge cover and the outer surface of the heating cylinder and scatters toward the injection device, it collides with the rear plate of the purge cover and is prevented.

In another purge cover device according to the present invention,
An exhaust hood is formed above the purge cover so that it can be connected to an exhaust duct.

Thus, the high-temperature air stored above the inside of the purge cover is discharged from the exhaust hood to the outside via the exhaust duct and processed like white smoke generated at the time of purging.

In still another purge cover device according to the present invention, a plurality of small holes are provided on the upper surface of the purge cover, and a rebound means is provided below each of the small holes.

As a result, the high-temperature air generated inside the purge cover is discharged upward from the small holes on the upper surface. Also, since the illumination of the factory ceiling enters through the small hole on the upper surface, the inside of the purge cover does not become extremely dark. Furthermore, the molten metal spouted from the nozzle and the molten metal scattered upward due to secondary scattering are
It collides with the inner upper surface of the purge cover and the rebound means, and is prevented from flying outside.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on embodiments with reference to the drawings. Note that the same or equivalent parts as those in the conventional example are denoted by the same reference numerals, and description thereof will be omitted.

(First Embodiment) FIGS. 1 and 2 show a first embodiment of the present invention.

In the purge cover device of the present embodiment, two guide bars 23 are attached to the upper part of the front of the purge cover 11 in a direction perpendicular to the direction of movement of the nozzle 3 so as to be slidable on the guide bar 23. The purge plate 16 is fixed so as to straddle the two fitted guide cylinders 24. The purge plate 16 includes a ceiling plate 26 that is bent at right angles to a purge surface 25 facing the nozzle 3, a receiving plate 28 including a flow lower surface 27 that is inclined toward the nozzle 3, and a guide tube 24 that holds both sides of the receiving plate 28. It consists of two fixed side plates 29.

A slide handle 30 and a cam plate 31 are fixed on the non-operation side (opposite side of the operation side) of the purge plate 16. The slide handle 30 extends in parallel with the direction of movement of the nozzle 3, is bent upward at the rear of the purge cover 11, and has a slot 3 provided on the upper surface of the purge cover 11.
2, a grip portion 33 extending upward and having a non-slip notch is provided at the upper end. On the fixed board side of the long hole 32,
A baffle plate 34 is attached downward.

As shown in FIGS. 2 (b) and 2 (c), the cam plate 31 is provided with a slope 35 at the tip, and a trapezoidally recessed lock groove 36 is provided slightly inside. A cam hole 37 through which the cam plate 31 passes is provided on the non-operation side of the purge cover 11, and a limit switch 38 is attached to a position where the cam plate 31 protrudes to the non-operation side. The pressure receiving roller 41 of the limit switch 38 can be fitted into the lock groove 36. The limit switch 38 includes the inspection door 13
Like the limit switch 14, a cover 39 for protecting the switch and preventing malfunction is attached.

A rear plate 22 provided with a notch 40 for preventing interference with the heating cylinder 1 and the like is attached to the injection device side of the purge cover 11.

Next, the operation of the purge cover device will be described.

When performing the purging operation, after the nozzle 3 is retracted, the slide handle 30 is pulled to the operation side,
The state shown in FIG. When purging is performed in this state, the purged molten metal collides with the purge surface 25 of the receiving plate 28,
It flows down the lower flow surface 27 and flows down into the purge tray 10. When the amount to be purged is large and the molten metal flows from the purge surface 25 in the horizontal direction, the molten metal hits the side plate 29 and changes its direction, and flows down into the purge tray 10.

When the molding operation is to be performed, the slide handle 30 is pushed to the side opposite to the operation side to bring the state shown in FIG.
At this time, after the pressure receiving roller 41 of the limit switch 38 rides on the inclination 35 of the cam plate 31 and operates, the lock groove 3
6 and stop. The depth of the lock groove 36 is set so that the operation of the limit switch 38 continues even when the pressure receiving roller 41 is fitted, and this operation signal allows the purge plate 16 to move to the retracted position, that is, the nozzle 3 to move forward. Is detected by the control device of the molding machine.

As a method for holding the purge plate 16 at the retracted position, a dedicated lock component such as a roller catch or a magnet catch may be used. In this embodiment, the fitting between the pressure receiving roller 41 and the lock groove 36 is performed. Since it is used, the device can be further simplified.

Further, secondary scattering occurs due to an erroneous operation or the like, and even if the molten metal tries to scatter toward the injection device through the gap between the purge cover 11 and the outer surface of the heating cylinder 1, the rear plate of the purge cover 11 may be used. Collision 22 is prevented.

There is also a metal injection molding die in which the spool bush 6 is provided below the center of the die 5, and such a die is shown in FIG. As described above, the molding machine is provided with a mechanism capable of aligning the sprue bush with the lower side gate hole 48 of the fixed plate 12 and attaching the mold, and moving the entire injection device 2 downward with respect to the mold clamping device 4. However, since the purge cover 11 of the present embodiment has a space below and the purge plate is formed to be long vertically, even if the entire injection device 2 is moved downward, the purge Work can be done.

(Second Embodiment) Next, a second embodiment will be described with reference to FIG. Parts that are the same as or equivalent to those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

In the purge cover device of this embodiment, the exhaust hood 42 is formed so that the upper surface of the purge cover 11 is raised at the center, and the exhaust port 43 provided at the highest position is connected to the exhaust duct 44. In order to improve the exhaust performance, the slide handle 45 is attached to the purge cover 11.
The rear plate 22 is formed so as to pass through a long hole 46 provided at a relatively high position.

The high-temperature air staying above the inside of the purge cover 11 is discharged from the exhaust hood 42 to the outside through the exhaust duct 44 and treated like the white smoke generated at the time of purging. Therefore, there is no danger that the reliability of the low-priced parts is reduced, and that the worker who opens and operates the inspection door 13 is exposed to high-temperature air.

Third Embodiment A third embodiment will be described with reference to FIG. Parts that are the same as or equivalent to those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

A plurality of small holes 20 are formed on the upper surface of the purge cover 11.
Provided below each of the small holes 20.
1 is installed.

In the purge cover device of this embodiment, the high-temperature air generated inside the purge cover 11
Since it is discharged upward from 0, it does not stay inside. Further, since the illumination of the ceiling of the building enters through the small hole 20 on the upper surface, the inside of the purge cover 11 does not become extremely dark, and it is not necessary to provide a dedicated illumination means. The molten metal scattered further upward collides with the inner upper surface of the purge cover 11 and the rebound plate 21 and is prevented from scattering outside the purge cover 11.

In the above-described embodiment, the rectangular small hole 20 and the flat plate rebound plate 21 are used. However, the small hole 20 may be made circular, the rebound plate 21 may have a curved surface, or a pipe may be attached instead. .

[0049]

According to the first aspect of the present invention, the molten metal purged from the nozzle during the purging operation is received by the purge plate and falls into the lower purge tray, so that it can be easily collected. At the time of molding, the purge plate can be slid to the retracted position, which does not hinder the molding operation.

According to the second aspect of the present invention, if the electric control of the molding machine is set so that the forward movement of the nozzle cannot be started unless it is confirmed that the purge plate is at the retracted position, the nozzle and the purge Since collision with the plate is avoided, damage to the nozzle, heater, and its electrical wiring can be prevented.

According to the third aspect of the present invention, further, 2
Even if the scattered molten metal attempts to scatter to the injection device side through the gap between the purge cover and the outer surface of the heating cylinder, the molten metal collides with the rear plate of the purge cover and is blocked. There is no damage to workers and no harm to workers.

According to the present invention, the purge cover can be easily slid to the retracted position.

According to the fifth aspect of the present invention, high-temperature air inside the purge cover is discharged from the exhaust hood and treated similarly to white smoke generated at the time of purging, so that heat resistance is low. There is no risk of reducing the reliability of the parts, and there is no danger that the worker opening the inspection door and working will be exposed to the hot air.

According to the sixth aspect of the present invention, the high-temperature air inside the purge cover is discharged upward from the small hole on the upper surface,
It does not stay inside. Further, since the illumination of the ceiling of the factory enters through the small hole on the upper surface, the inside of the purge cover is extremely darkened. Therefore, it is not necessary to provide a dedicated illumination means. Further, the molten metal scattered upward collides with the inner upper surface of the purge cover and the rebound means and is prevented from scattering outside the purge cover.

[Brief description of the drawings]

FIG. 1 shows a purge cover device according to a first embodiment.
2A is a sectional view taken along line DD of FIG. 2B, and FIG. 2B is a sectional view taken along line AA of FIG.

FIG. 2A is a view taken in the direction of arrow B in FIG. 1B, and FIG.
(A) is a view on the line CC, and (c) is an enlarged view of a portion E of (b).

FIG. 3 shows a purge cover device according to a second embodiment.
(A) is a GG line sectional view of (b), (b) is a FF arrow view of (a).

FIG. 4 shows a purge cover device according to a third embodiment.
(A) is a cross-sectional view taken along the line II of (b), and (b) is a view taken along the arrow H of (a).

FIG. 5 shows a conventional purge cover device. (A) is a view on arrow K in (b), and (b) is a view on arrow JJ in (a).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating cylinder 2 Injection device 3 Nozzle 4 Mold clamping device 5 Die 6 Sprue bush 7 Sprue hole 8 Cavity 9 Casting sand 10 Purge tray 11 Purge cover 12 Fixing plate 13 Inspection door 14 Limit switch 15 Nozzle insertion hole 16 Purge plate 17 Heater REFERENCE SIGNS LIST 20 small hole 21 bounce-back plate (bounce-back means) 22 rear plate 23 guide bar 24 guide cylinder 25 purge surface 26 ceiling surface 27 flow lower surface 28 receiving plate 29 side plate 30 slide handle (slide means) 31 cam plate 32 long hole 33 grip portion 34 baffle plate 35 slope 36 lock groove (holding means) 37 cam hole 38 limit switch (checking means) 39 cover 40 notch 41 pressure receiving roller 42 exhaust hood 43 exhaust port 44 exhaust duct 45 slide handle 46 long hole 47 window 48 lower side Mouth mouth hole

Claims (6)

[Claims] 1. A purge cover (11) installed at a position in contact with a fixed plate (12) and covering an open upper surface, a front surface, and a rear surface around a nozzle (3) in a U shape. Metal injection molding, characterized in that a purge plate (16) that blocks the front of the metal plate is installed, and during molding, the purge plate (16) is slid to a retreat position that does not interfere with the nozzle (3) or the heating cylinder (1). Machine purge cover device. 2. A method according to claim 1, further comprising the step of: providing a confirmation means for confirming that the purge plate has been slid to the retracted position, and providing a retaining means for retaining the purge plate at the retracted position. The purge cover device for a metal injection molding machine according to claim 1, wherein: 3. A purge cover (11), on the injection device side,
3. A purge cover device for a metal injection molding machine according to claim 1, wherein a rear plate (22) that does not interfere with the outer surface of the heating cylinder (1) is provided. 4. A slide means (3) for sliding the purge plate (16) from outside the purge cover (11).
The purge cover device for a metal injection molding machine according to claim 1, wherein 0) is provided. 5. The metal injection device according to claim 1, wherein an exhaust hood (42) is formed on an upper surface of the purge cover (11) and connected to an exhaust duct (44). Purge cover device for molding machines. 6. The purge cover according to claim 1, wherein a plurality of small holes are provided on an upper surface of the purge cover, and a bounce-back means is provided below each of the small holes.
A purge cover device for a metal injection molding machine according to any one of claims 4 to 4.